Borealis is relatively new to the fat bike market, but made a very big impression with the introduction of the Yampa and Echo. The Crestone is a refinement of those technologies, with improved geometry, frame design elements, and quality craftsmanship. Much of what was missing on the Yampa can be found on the Crestone after months of rider and market input. The rear QR was finally replaced with a proper thru axle. The rear carbon dropout was reinforced. The standover clearance was decreased. The “calf-bang factor” was improved. Overall geometry improved, making a much more capable bike. You can check out details of the Crestone here on their webpage.

A nice-looking ride, the Crestone is redesigned for more aggressive riding while keeping the race-oriented riders in mind

The Deets (from Borealis)

The Crestone is a closed mold, carbon fiber bike frame that represents the most advanced geometry for fat bikes.

New impact and fatigue standards to match the demands of riders who might ride a fat bike more aggressively

Totally new frame design developed to be more durable and thrilling to ride, while maintaining an aesthetic becoming of a high performance product

Weighs in at 150 grams less than the Echo

Available in two new colorways

Advanced carbon molding with state of the art production

Designed with reduced stand over height–top tube drops by one half inch

Available with SRAM XO1 or XX1 components

Internal routing ports galore adorn the Crestone, but plug these up or water will find its way into the frame

Geometry and Sizing

I was sent a size-medium frame after perusing the geometry chart, which is the same size that I typically ride. Top tube and seat tube height are important, but standover height and reach are my main concerns when sizing a bike. The geo is pretty spot on and summed up well in this chart from Borealis:

S

M

L

XL

S

M

L

XL

Effective Top Tube

23.02 in

24.01 in

24.67 in

24.72 in

584.8 mm

609.8 mm

626.6 mm

627.9 mm

Seat Tube Center to Top

15.04 in

17.01 in

19.06 in

21.02 in

382 mm

432 mm

484 mm

534 mm

Head Tube

4.13 in

4.72 in

5.31 in

5.91 in

105 mm

120 mm

135 mm

150 mm

Seat Tube Angle

73 deg

73 deg

73 deg

73 deg

73 deg

73 deg

73 deg

73 deg

Head Tube Angle

70 deg

70 deg

70 deg

70 deg

70 deg

70 deg

70 deg

70 deg

Standover Height

Due to various rim and tire options stand over is not identified.

Chainstay

18.07 in

18.07 in

18.07 in

18.07 in

459 mm

459 mm

459 mm

459 mm

BB Drop

2.36 in

2.36 in

2.36 in

2.36 in

60 mm

60 mm

60 mm

60 mm

Reach

16.04 in

16.65 in

17.22 in

17.76 in

407.3 mm

423 mm

437.5 mm

451.2 mm

Stack

23.50 in

24.05 in

24.61 in

25.16 in

597 mm

610.9 mm

625 mm

639.1 mm

Frame

Borealis has been working hard on shoring up their carbon while making a capably-light frame, and it shows.

The color I was sent pays homage to the Colorado flag, and the paint stands out with a lot of pop.

Ode to the Centennial state, the Crestone has paint that looks superb

Components

Borealis was kind enough to send over the top-shelf XX1 build for review, spec’d with a Bluto and the new Maxxis Minion FBF 4.8s. Despite being a relatively-light frame using the lightest components possible, the build came in at just over 29.8lbs with flat pedals (without a dropper), due mainly to aluminium wheels and large, meaty Minions. The tires alone weigh 3.6 lbs, each! Despite the weight, it was a solid build that never felt heavy.

The Maxxis Minion FBF 4.8s are on the hefty side at 1620 grams, but have a lot of traction, float well, and paddle well.

Cockpit

Borealis spec’d this ride with a feathery but stout RaceFace NEXT 750mm bar and 70mm RaceFace stem, Ergon grips, Ergon saddle, and lightweight NEXT carbon post. No quick release was included on the post, which would be a nice addition given the lack of a dropper.

A 70mm stem holds the RaceFace bars and is solid

Brakes

I was delighted to see that this bike came with the new SRAM Guide RSC Ultimate brakes. I have had SRAM Guide RSC brakes installed on my personal bikes for the past year, including my personal fat bike. These are quiet, modulate well, and stop on a dime. For a comprehensive review of these brakes, look here. I’ve tested the RSCs on the singletrack, at the DH park, and on several fat bikes.

Drivetrain

Borealis spared no expense with the lightest, most versatile crankset on the market: the RaceFace NEXT SL. I have also had a lot of experience with these, which I will expound upon in my final review, and compare it to other bikes I have tried them on. They also supplied a gold KMC chain mated to a RaceFace machined 30T chainring, XX1 cassette, and XX1 rear derailleur. An XX1 shifter handles the tranny.

Super light and stiff cranks, the Next SLs are lustworthy

Fork

The newest model of the RockShox Bluto with the RTC3 came with the Crestone, which was set at 100mm of travel and has quite a bit more adjustment than the first generation of the Bluto, which I reviewed here.

Shiny new knobs on the Bluto and an improved damper suggest even more promise out of an already trustworthy fatty fork

Wheels

Borealis included the house-branded 80mm Turnagain hubs laced to beautiful, shiny, anodized blue Turnagain hubs. The hubs are 150mm in the front to accommodate the width of the Bluto, and 197mm in the rear. This, along with wide stays, allows 5 inch tires to clear with ease if the beefy Minion 4.8s aren’t enough to float your boat. The Minions are supple with a 120tpi casing and have very aggressive knobbies. I set these up tubeless immediately, and the Minions were by far the easiest tubeless tire to mate to any rim I’ve tried.

The hubs are gorgeous, have a discernable click when freespinning, and seem to have very quick engagement

Here is a complete summary of the build from the Borealis website:

Frame

Borealis Crestone

Fork

Borealis Carbon Rigid Fork

Headset

Cane Creek 40

Hubs

Turnagain: Front 15×150 Rear 12×197

Rims

Turnagain FR 80 FTD Tubeless

Spokes

Wheelsmith Black DB

Nipples

Wheelsmith Black Alloy

Rim Strips

Turnagain RS80

Tires

26×4.8″ Maxxis Minion FBF EXO TR

Tubes

Turnagain MagnumFAT

Bar

Race Face Next SL 35 740mm

Stem

Race Face Turbine 70mm

Post

Race Face Next SL 31.6mm

Saddle

Ergon SME30 EVO “Borealis”

Grips

Ergon GA2

Crankset

Race Face Next SL 30t 175mm

Front Derailleur

Rear Derailleur

SRAM XX1 11 Speed

Chain

KMC X11

Cassette

SRAM XG-1199 10-42

Shifters

SRAM XX1 11 Speed

Brakes

SRAM Guide Ultimate w/Centerline 180/160

DT/CS Protector

Lizard Skins

MSRP: $5,850

MSRP with a RockShox Bluto Fork: $6,050

I have already put some miles in on this bike and cannot wait to log some more! Let me know what questions you may have, and I will do my best to answer them during my final review. Thanks!

Here are some more product shots of the Crestone XX1 build:

Capable in any terrain, so far the Crestone has been a blast to ride

Internal routing for the rear brake line

The SRAM XX1 rear derailleur mates perfectly with the KMC chain and makes a very good chainline to accommodate 5-inch tires

SRAM XX1 cassette. I love the new rear thru axle setup

SRAM Guide RSC brakes and the NEXT carbon bar

A closer shot of the Centerline 180mm rotor mated to the awesome blue hub

Nice and tidy, I like the way the rear caliper sits in the stays

A close up of the Ergon grip

The Ergon saddle is definitely race-inspired

A quick release would be a nicer touch, but I took this photo to illustrate the beautiful blue paint and quality carbon molding

80mm Turnagain rims setup tubeless with ease

Rear stays have no problem clearing the largest tires out there

I think Borealis made a conscious effort to reduce the “calf-bang factor” and maximize tire clearance

Paul stumbled upon mountain biking in his twenties after upgrading his rigid purple Roadmaster to a shiny yellow Cannondale Super V900 . He resides in central Colorado, where he preaches the gospel of the (true) fat tire and he's been known to ride excessive amounts of wheelies. He is known for being surly, is opinionated, delights in run on sentences, and probably doesn't care what you think. He believes in following the rules. He frowns on people who don't do the right thing, or people who take themselves too seriously. His biggest pet peeve are Subarus that creep along slowly in the left lane. His best conversations are often with himself. When he is not riding, he appreciates exotic espresso, craft libations, Led Zeppelin, and making excuses. He's been known to jump out of perfectly good aircraft and pet sharks underwater (simultaneously). His fat bike is more prepared for the zombie apocalypse than you are. When he is not trying to be funny, Paul also likes traveling the world, photography, being a dad, and chronicling his crotchety shenanigans. Platypus. That is all.Read more...